P-Sulphophenoxy-phenylazo indoles

ABSTRACT

Synthetic fibre materials, especially polyester fibres, are dyed in yellowish to orange-red shades with good fastness to light and washing if dyestuffs of the formula ##STR1## wherein K denotes the radical of a coupling component of the indole series, 
     R denotes alkyl, cycloalkyl, aralkyl or aryl and the ring A can contain further non-ionic substituents which are customary in dyestuff chemistry, are used for dyeing.

The invention relates to disperse dyestuffs of the formula ##STR2## wherein K denotes the radical of a coupling component of the indole series,

R denotes an optionally substituted alkyl, cycloalkyl, aralkyl or aryl radical and the ring A can contain further non-ionic substituents which are customary in dyestuff chemistry. Preferred dyestuffs correspond to the formula ##STR3## wherein R₁ represents alkyl or aryl,

R₂ represents hydrogen, halogen, CN, CF₃, NO₂, Q₁, --OQ₁, --COOQ₁, --CONQ₁ Q₂ or NHCOQ₁,

R₃ represents hydrogen, halogen, CF₃, Q₁ or OQ₁,

R₄ represents halogen or Q₁,

R₅ represents Q₂ and

R₆ represents hydrogen, halogen, Q₁, OQ₁ or COOQ₁,

wherein

Q₁ denotes alkyl or aryl and

Q₂ denotes hydrogen, alkyl or aralkyl.

The abovementioned alkyl, aralkyl, cycloalkyl and aryl radicals can contain further non-ionic substituents.

Suitable alkyl within the scope of this invention is, in particular, alkyl with 1 to 4 C atoms, which can be optionally further monosubstituted by cyano, halogen, such as chlorine, bromine or fluorine, hydroxyl or C₁ -C₄ -alkoxy, for example methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert.-butyl, cyanoethyl or 2-chloroethyl.

Suitable aryl is, in particular, phenyl which is optionally monosubstituted to trisubstituted by halogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, nitro, cyclohexyl or phenyl.

"Bulky" radicals are in those positions where they cause no steric hindrance, for example tert.-butyl in the m-position or p-position of a phenyl radical.

Suitable halogen is chlorine, bromine or fluorine, but preferably chlorine.

Suitable aralkyl is, for example, benzyl or phenethyl.

Suitable cycloalkyl is, for example, cyclopentyl, cyclohexyl and cycloheptyl.

Particularly preferred dyestuffs are those of the formula ##STR4## wherein R₁ ' represents phenyl which is optionally monosubstituted to trisubstituted by C₁ -C₄ -alkyl, chlorine, nitro, cyclohexyl or phenyl,

R₂ ' stands halogen, cyano, trifluoromethyl, nitro, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,

R₃ ' stands H, halogen, trifluoromethyl, C₁ -C₄ -alkyl or

C₁ -C₄ -alkoxy,

R₄ ' stands C₁ -C₄ -alkyl or phenyl and

R₅ ' stands C₁ -C₄ -alkyl, benzyl or phenethyl.

Very particularly preferred dyestuffs are those of the formula ##STR5## wherein R₁ " represents phenyl, tolyl or chlorophenyl,

R₂ " and R₃ " represent chlorine,

R₄ " represents methyl or phenyl and

R₅ " represents C₁ -C₄ -alkyl.

The new dyestuffs are prepared in a manner which is in itself known, by customary diazotisation and coupling reactions.

The dyestuffs according to the invention are of very high tinctorial strength and are suitable for dyeing synthetic fibre materials, in particular those consisting of polyamides, such as, for example, polycaprolactam, polyhexamethylenediamine adipate or polyaminoundecanoic acid, but very particularly those consisting of polyester, such as polyethylene terephthalate and poly-1,4-cyclohexanedimethylene terephthalate, from aqueous liquors or organic solvents. The types of fibres mentioned are dyed in yellow to orange-red shades of good colour yield and with good fastness properties in use, such as, for example, fastness to light and wet processing.

EXAMPLE 1

31.8 g of 4-amino-2,5-dichloro-benzenesulphonic acid phenyl ester are suspended in 400 ml of water and 30 ml of concentrated hydrochloric acid. 73 ml of a 10% strength sodium nitrite solution are added dropwise at 0°-5° C. in the course of 15 minutes. After stirring for one hour at the temperature indicated, the excess nitrite is destroyed with amidosulphonic acid. This diazonium salt suspension is then added dropwise to a slurry of 22 g of 1-methyl-2-phenyl-indole in 100 ml of concentrated hydrochloric acid at 0°-5° C. in the course of 30 minutes. After stirring for 3 hours, the pH value is adjusted to 3.5 by slowly adding 10% strength sodium hydroxide solution. A further 3 hours thereafter, the precipitate is filtered off, washed with water and dried at 60° C. in a vacuum drying cabinet. This gives 45 g of a dyestuff of the formula ##STR6##

Dyeing Examples

(1) 1 part of the dyestuff obtained according to Example 1 and finely dispersed by customary processes is stirred into 2,000 parts of water. The mixture is adjusted to a pH value of 5 to 6 with acetic acid, and 4 parts of ammonium sulphate and 2 parts of a commercially available dispersing agent based on a naphthalenesulphonic acid/formaldehyde condensation product are added. 100 parts of a polyester fabric based on polyethylene glycol terephthalate are introduced into the dye liquor thus obtained and dyeing is carried out at 120°-130° C. for 11/2 hours. After subsequent rinsing, after-treatment by reduction with a 0.2% strength alkaline sodium dithionite solution for 15 minutes at 60° C., rinsing and drying, a reddish-tinged yellow dyeing with good fastness properties, in particular good fastness to light and sublimation, is obtained.

(2) 100 parts of a fabric consisting of polyethylene terephthalate fibres are introduced, at room temperature, into a dyebath which is prepared from 1 part of the monoazo dyestuff of Example 1 and 1,000 parts of tetrachloroethylene. The bath is heated to 110° C. in the course of 20 minutes, whilst vigorously circulating the liquor, and is kept at this temperature for 45 minutes. The liquor is then removed and the fabric is rinsed with fresh tetrachloroethylene at 40° C. After removing the rinsing liquor, the dyed material is freed from adhering solvent by spinning and drying in a stream of air. A strong reddish-tinged yellow dyeing of good general fastness properties is obtained.

(3) 0.1 g of the highly dispersed dyestuff according to Example 1 is introduced, at 40° C., into 1 l of water, which also contains 0.2 g of sodium dinaphthylmethanesulphonate and 0.3 g of cresotic acid methyl ester. 10 g of a fabric consisting of polyethylene terephthalate are introduced into this bath, the temperature of the dyebath is increased to 100° C. in the course of about 20 minutes and dyeing is carried out at this temperature for 60-90 minutes. A strong reddish-tinged yellow dyeing with good fastness to sublimation and light is obtained.

Similar dyestuffs which have similar properties to that obtained according to Example 1 result when the following diazo components containing sulphonic acid ester groups are diazotised and coupled with the following indole coupling components. The dyestuffs dye synthetic fibre materials, such as polyesters and polyamides, in the given colour shades with good fastness properties, for example good fastness to light, wet processing and sublimation.

    __________________________________________________________________________     Ex-                                            Colour                          ample                                                                              Diazo component                Coupling component                                                                         Shade                           __________________________________________________________________________      2  4-amino-2,5-dichloro-benzenesulphonic acid 3-methyl-phenyl                                                    1-ethyl-2-phenyl-indole                                                                    golden                              ester                                      yellow                          3   4-amino-2,5-dichloro-benzenesulphonic acid 4-methyl-phenyl                                                    1-propyl-2-methyl-indole                                                                   yellow                              ester                                                                      4   4-amino-2,5-dichloro-benzenesulphonic acid 2-chloro-phenyl                                                    1-butyl-2-phenyl-indole                                                                    golden                              ester                                      yellow                          5   4-amino-2,5-dichloro-benzenesulphonic acid 4-chloro-phenyl                                                    1,2-dimethyl-indole                                                                        yellow                              ester                                                                      6   4-amino-2,5-dichloro-benzenesulphonic acid 2,4-dichloro-                                                      1-methyl-2-butyl-indole                                                                    yellow                              phenyl ester                                                               7   4-amino-2,5-dichloro-benzenesulphonic acid 2-ethyl-phenyl                                                     1-ethyl-2-phenyl-indole                                                                    golden                              ester                                      yellow                          8   4-amino-2,5-dichloro-benzenesulphonic acid 3,5-dimethyl-                                                      1-benzyl-2-phenyl-indole                                                                   golden                              phenyl ester                               yellow                          9   4-amino-2,5-dichloro-benzenesulphonic acid 4-nitro-phenyl                                                     1-methyl-2-methyl-indole                                                                   yellow                              ester                                                                      10  4-amino-3-chloro-benzenesulphonic acid 2,4,5-trichloro-                                                       1-ethyl-2-chloro-indole                                                                    yellow                              phenyl ester                                                               11  4-amino-3-nitro-benzenesulphonic acid 4-chloro-2-methyl-                                                      1-methyl-2-phenyl-indole                                                                   golden                              phenyl ester                               yellow                          12  4-amino-2-chloro-5-cyano-benzenesulphonic acid 2-ethyl-                                                       2-phenyl-indole                                                                            orange                              phenyl ester                                                               13  4-amino-2,5-dimethyl-benzenesulphonic acid 2,3-dimethyl-phenyl                                                1-octyl-2-phenyl-indole                                                                    golden                              ester                                      yellow                          14  4-amino-3-chloro-6-methoxy-benzenesulphonic acid 2,4-dimethyl-                                                1-phenethyl-2-methyl-                                                                      yellow                              phenyl ester                   indole                                      15  4-amino-2-methoxy-5-nitro-benzenesulphonic acid 4-chloro-                                                     1-methyl-2-phenyl-indole                                                                   orange                              2,5-dimethyl-phenyl ester                                                  16  4-amino-3-ethoxy-benzenesulphonic acid 2,5-dimethyl-phenyl                                                    1-propyl-2-methyl-indole                                                                   yellow                              ester                                                                      17  4-amino-2,5-di-trifluoromethyl-benzenesulphonic acid                                                          1-methyl-2-phenyl-5-                                                                       golden                              isopropyl-phenyl ester         methody-indole                                                                             yellow                          18  4-amino-3-trifluoromethyl-benzenesulphonic acid 4-tert.-                                                      2-phenyl-7-ethyl-indole                                                                    orange                              butyl-phenyl ester                                                         19  4-amino-2,5-dichloro-benzenesulphonic acid 2-isopropyl-5-                                                     2-phenyl-5-carboxyethyl-                                                                   orange                              methyl-phenyl ester            indole                                      20  4-amino-3-methyl-benzenesulphonic acid x-nonyl-phenyl                                                         1-methyl-2-phenyl-indole                                                                   golden                                                                         yellow                          21  4-amino-3-trifluoromethyl-benzenesulphonic acid 4-cyclo-                                                      1-ethyl-2-phenyl-indole                                                                    yellow                              hexyl-phenyl ester                                                         22  4-amino-3-chloro-5-methyl-benzenesulphonic acid 4-phenyl-                                                     1-methyl-2-phenyl-indole                                                                   golden                              phenyl ester                               yellow                          23  4-amino-3-carboxymethyl-benzenesulphonic acid phenyl                                                          1-propyl-2-methyl-indole                                                                   yellow                          24  4-amino-3-acetylamino-benzenesulphonic acid 3-methyl-phenyl                                                   1-methyl-2-phenyl-indole                                                                   golden                              ester                                      yellow                          25  4-amino-2,5-dichloro-benzenesulphonic acid butyl ester                                                        1-ethyl-2-phenyl-indole                                                                    golden                                                                         yellow                          26  4-amino-3-trifluoromethyl-benzenesulphonic acid cyclohexyl                                                    1-methyl-2-methyl-indole                                                                   yellow                              ester                                                                      27  4-amino-3-chloro-benzenesulphonic acid octyl ester                                                            1-methyl-2-phenyl-indole                                                                   golden                                                                         yellow                          28  4-amino-benzenesulphonic acid 3-methyl-cyclohexyl ester                                                       1-methyl-2-phenyl-indole                                                                   yellow                          29  4-amino-2,5-dichloro-benzenesulphonic acid ethyl ester                                                        1-ethyl-2-phenyl-indole                                                                    golden                                                                         yellow                          30  4-amino-2,5-dichloro-benzenesulphonic acid phenyl ester                                                       1-methyl-2-phenyl-5-                                                                       scarlet                                                            carboxyethyl-indole                         __________________________________________________________________________ 

We claim:
 1. A disperse dyestuff of the formula ##STR7## wherein R₁ ' is phenyl or phenyl monosubstituted to trisubstituted by C₁ -C₄ -alkyl, chlorine, nitro, cyclohexyl or phenyl,R₂ ' is halogen, cyano, trifluoromethyl, nitro, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy, R₃ ' is H, halogen, trifluoromethyl, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy, R₄ ' is C₁ -C₄ -alkyl or phenyl, and R₅ ' is C₁ -C₄ -alkyl, benzyl or phenethyl.
 2. A disperse dyestuff according to claim 1, of the formula ##STR8## wherein R₁ " represents phenyl, tolyl or chlorophenyl,R₂ " and R₃ " represent chlorine, R₄ " represents methyl or phenyl and R₅ " represents C₁ -C₄ -alkyl.
 3. A disperse dyestuff according to claim 1, of the formula ##STR9## 